Cap



Patented Sept. 5,y 1944 y.

NT vorifice I Charles E.'McManus, SpringLake,l N. J., and Giles B.Cooke, Baltimore, Md., assignors to Crown Cork Seal Company, Inc.,Baltimore, Md., a corporation of New York Application July Z5, 1940,Serial No. 347,538

' 1 claim. .(01.215-39) This invention relates to closures of theskirted type having a cushion liner disposed therein.

The cap of the present invention is provided with a protective coatingapplied by a single operation as by spraying on the surface of the thecap skirt including the raw edge thereof. This continuous facing, whenthe cap is sealed upon a container, is interposed between the contentsand the cushion liner and acts in a manner similar to center spots andoverall facings of paper and foil which have heretofore been used.Moreover, the coating on the inner wall of the cap skirt andparticularly the raw or free edge thereof not only assures additionalrustproofness, buteiiectively closesv any pores or bruised or otherwiseuncovered portions in the lacquer surface of the cap.

A particularly important feature of the invention resides in forming thecontinuous film on the interior exposed surface of an assembled cap.` i.e., shell with liner therein, by a single operation. We have found byspraying a solution 'of protective material into the interior of theassembled cap, that on drying, a thin continuous film is producedcoextensive with both the area cushion liner and the adjacent interiorwall of of the liner and the entire exposed area of the Caps having thethus is not limited in its application to the details of constructionand arrangements of parts illustrated in the accompanying drawing, sincethe invention is capable of other embodiments and of being practiced orcarried out in various ways. Also, vit is to be understood that thephraseology or terminology employed herein is for the purpose ofdescription and not of limitation, and it is not intended to limit theinvention claimed herein beyond the requirements of the prior art.

In the drawing,

Figure 1 is'a sectional view showing a crown cap provided with aprotective film in accordance with this invention; and

Figure 2 is a bottom elevation of a. crown cap.

Referring to Figure 1, there `is shown for purposes of illustration ametal crown cap having a top I0 and a depending `crimped skirt II. Theinvention may be employed with any desired skirted closure, for example,a screw cap, a lug cap, or a pressed-on cap. The cap shell is`customarily coated with a suitable protective lacquer both interiorlyand exteriorly, and there is assembled within the shell a cushion linerI2 united thereto by a. suitable adhesive. This cushion liner iscomposed of various materials such as paper, rubber, natural orcomposition cork. Cork liners are most generally used.`

'Ihe continuous protective fllm'in accordance with this invention is ofa thickness about substantially five ten thousandths to threelthousandths of an inch, and is indicated at .|3. -It constitutes acontinuous, adherent facing upon the'exposed surface of the liner I2 andthe adjacent interior wall of the cap skirt including its raw or freeedge I4. In the case of caps such as crown caps, lug caps and screwcaps, or other skirted closures in which the skirt has 'an irregularcontour, the film is lcoextensive with and adhered to the entire exposedsurface of the interior of the cap. 'I'hat is'to say, in crown caps forexample, the film covers the cushion liner and extends integrallytherefrom to continuously cover both the hills and valleys of thecrimped 'or corrugated area and the raw edge.

As explained above, the .facing layer on the l The protective materialemployed is one which4 is adherent to metal, the lacquer coating, andthe composition liner. It also has the necessary resistant properties sothat it will not react with the contents such as beverages and foods andwill impart rustproofness and abrasion resistance to the cap shell,particularly at the raw edge of the same. Preferably, dilute solutionsof the lm' forming material are employed, e. g., 2 to 10 -percentsolutions in a suitable low boiling solvent..

but greater concentrations may be used in some cases, e. g., up to 30%dependent upon the nature of the coating materials. We prefer to usesubstances such as Vinylite" resin, chlorinated rubber, polyvinyl acetalresin and ethyl cellulose, but

numerous other odorless andv tasteless coating Of particular importance,the illm is applied effectively to assure rapid and inexpensivemanufacture by spraying one of the solutions above mentioned upon theinterior of the cap. In other words, in a single operation upon theassembled cap, i. e., the cap shell and liner therein, We

are able to produce the continuous facing film of the same material onthe liner and on the I adjacent inner wall o! the cap Skirt includingits raw edge. We prefer to accomplish the operation by spraying. butsatisfactory results may be obtained by-brushing the solution upon theinterior of the assembled cap or by dipping the cap in the solution.

After the solution has been applied to the cap, the protective film isdeposited from the solution by drying, care being taken to remove alltraces of solvent.

In some cases, as where the lm I3 lacks complete continuity between thecushion liner I2 and thev interior Wall surface of the cap, when the capsuch as a crown is crimped upon the sealing lip of the container, theadjacent surfaces of the liner and skirt are brought together so thatthe coating I3 for all practical purposes,

both the sealing liner and the adjacent exposed surface of the cap skirtincluding the raw edge thereof, and thereby a. continuous coating iaproduced which bridges the joint between the sealing linerI and the capskirt, as shown in Fig. l.

The provision of the illm forming protective materials above describedis particularly advantageous' with certain types of cushion liners suchas those made of newsboard or paper pulp having the conventional glazedpaper facing. These are relatively hard as compared to cork or corkcomposition, and the 111m being tough. compressible and resilientsubstantially assists in forming an eiective seal between the cap andthe sealing lip of the container.

We claim:

A cap having a top and a skirt, a cushion liner within the cap, and aprotective nlm coextensively coated and adhered on the exposed surfaceof the liner and the entire adjacent interior exposed surface of the capskirt including the raw edge thereof, the lm on the liner and the filmon the skirt being-of the same material and continuous with each otherand bridging the Joint between the cushion liner and the cap skirt.

CHARLES E. MCMANUS. GILES B. COOKE.

